textproduct: Quad Cities

KEY MESSAGES

- A strong storm system will bring the threat for severe storms once again to our area through this evening. SPC continues to highlight nearly our entire area in an Enhanced Risk (level 3 of 5) for severe weather.

- A flood watch has been issued for much of the area through tonight for the potential of excessive rainfall with the final round of storms this afternoon/tonight. Soils across the area are saturated north of I-80 and very moist south of I-80.

- Much cooler conditions are expected this weekend. Unseasonably cool temperatures in the 30s Saturday night and Sunday night will bring the potential for frost/freeze, especially in our north.

- Area rivers are on the rise from the recent rounds of heavy rain, and heavy rainfall later today may push them even higher. Refer to the hydro section below for more details.

SHORT TERM /THROUGH TONIGHT/

Issued at 1252 PM CDT Fri Apr 17 2026

Convective initiation has occurred across eastern Iowa. The individual discrete cells will rapidly grow upscale into one or more broken lines ahead of the cold front.

The atmosphere is becoming increasingly moist so the storms will have plenty of fuel to produce heavy rainfall. The axis for the heavier rain is somewhat narrow but rainfall amounts of an inch in an hour will be possible with the stronger storms. Where storms linger or repeat over the same areas, rainfall amounts of 2 to 3 inches in a short time will be possible.

The pre-frontal line(s) of storms look to push east of the Mississippi in the 6-8 PM time frame with the cold front arriving during the mid to late evening hours. Very short range models which had been pointing to a solid line of storms with the front are now trending toward a scattered to broken line with not much thunder associated with it. This 'may' be an indication the convective allowing models are struggling with the overall forcing from the upper level system.

The bulk of the rain looks to end across the area by midnight but scattered rain showers along and immediately behind the front will linger past midnight. However, the overall trend will be decreasing areal coverage from west to east after midnight.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 306 AM CDT Fri Apr 17 2026

Much colder air will continue to move into the area for the weekend as a northwest flow pattern develops aloft. An area of high pressure will build into the area Saturday night, which could set up our first bout of frost/freeze conditions during the growing season. There does appear to be a mid-level trough sweeping through the area Saturday night, which could result in some cloud cover that could keep our temperatures from falling too much, limiting our frost/freeze potential. Despite this, the NBM probabilities of freezing temperatures Saturday night are still around 50-80% along and north of Interstate 80. Another night of frost/freeze conditions are possible Sunday night as well, with similar exceedance probabilities for freezing temperatures.

A quieter weather pattern will persist into early next week as a broad upper ridge remains in place through the central US. A larger trough begins to take shape across the western US into the latter portion of the week. Therefore, some warming and a move toward some smaller precipitation chances (20-40%) start to return to the area by Thursday with a larger storm system potentially nearing the region for Friday.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1225 PM CDT Fri Apr 17 2026

Convective initiation has begun over eastern Iowa with surface winds gusting to 30 knots. Very short range models indicate rapid upscale growth of TSRA through 00z/18. Discrete TSRA cells will grow upscale into a line that congeals along the Mississippi River by 00z/18. Based on forecast soundings, probability is high for wind gusts over 50 knots with the discrete cells and as the line forms. By 06z/18 the cold front will have swept through the area with widespread MVFR conditions and winds gusting up to 25 knots.

HYDROLOGY

Issued at 1136 AM CDT Thu Apr 16 2026

Discussion...

Over the past five days, multiple rounds of heavy rain have impacted eastern Iowa, northern Illinois and southern Wisconsin. Rainfall amounts have run from 2 to 5 inches of rain; much of this rain has been north of Highway 30.

Another round of heavy rain is forecast this afternoon and evening with amounts running from a half inch to around 1.5 inches. With area soils running from moist to near saturation, this additional rainfall will quickly run off into area waterways resulting in new or increased river flooding along with the potential for flash flooding.

Much of this rain is forecast to fall across southeast Iowa, west central Illinois and into northern Illinois. River basins impacted would be the Rock, lower Iowa, Skunk, Des Moines and La Moine.

Rock River...

Based on overall river forecasts and another round of heavy rain expected today, confidence is high (>80%) that the entire length of the Rock River will reach flood stage by the weekend and remain above flood stage into much of next week.

Mississippi River...

Routed flow coming down from the upper Mississippi, Wisconsin, Rock, Iowa and other tributary rivers will cause general rises along the length of the Mississippi. Based on the current routed flow and another round of heavy rain, confidence is high (>80%) that the Mississippi will reach flood stage from Muscatine down through Keithsburg and at Gregory Landing. Gladstone and Burlington are already above flood stage and will see additional rises as the additional routed flow arrives over the weekend and into next week.

Iowa Tributary Rivers...

Rivers in eastern Iowa are running high from the rounds of heavy rain. Flood warnings continue for the lower Wapsipinicon River near DeWitt and the Iowa River above Coralville near Marengo. Based on routed flow, the lower Cedar River near Conesville will go above flood stage over the weekend.

The North Skunk River near Sigourney is forecast to go above flood stage tonight with general rises expected farther downstream and on the Skunk River.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Flood Watch through late tonight for IAZ040>042-052>054- 064>068-077-078-088-089-099. IL...Flood Watch through late tonight for ILZ001-002-007-009- 015>018-024>026-034-035. MO...Flood Watch through late tonight for MOZ010.